BMS Bails on Checkpoint Inhibitor Teaming with CytomX, Stock Sinks

Bristol Myers Squibb_hapabapa/iStock

Pictured: BMS building in Brisbane, California/iStock, hapabapa

Bristol Myers Squibb is leaving CytomX scratching its head with the “unexpected decision” to discontinue its partnered program for a more potent version of the BMS immunotherapy Yervoy. CytomX announced the update with its 2023 financial results late Monday, sending its stock tumbling around 20% in premarket trading Tuesday. 

In an earnings call, CytomX CEO Sean McCarthy said BMS informed the company of its decision to terminate on March 6, following a broad internal portfolio review. The biotech intends to work with BMS to understand the data that led to the decision, according to McCarthy.  

BMS had prioritized the program, dubbed BMS-986288, as its lead next-gen CTLA-4 program and advanced it into Phase II studies last year. Utilizing CytomX’s Probody therapeutic technology, it is designed to be a more potent and less systemically toxic version of Yervoy, BMS’s CTLA-4-blocking antibody.  

Yervoy is currently approved for seven types of cancers including melanoma and colorectal cancer. The drug is one of BMS’ top cancer drugs, raking in over $2.2 billion in sales in 2023.This isn’t the first time a BMS decision has sent CytomX stock tumbling. In 2019, BMS reprioritized the pipeline after its Celgene acquisition and terminated three discovery programs with CytomX. That decision sent the biotech’s stock into a 30% nosedive. BMS paid $50 million to strike up the initial collaboration with CytomX nearly 10 years ago, paying $50 million at the time. 

However, the two will continue to work together in other collaborations involving T-cell engagers, which is the focus of most of CytomX’s partnered programs. The biotech also has deals with Amgen, Astellas, Moderna and Regeneron. 

CytomX is still eligible to receive $1.8 billion in contingent payments for development, regulatory and sales milestones for the ongoing collaboration programs with BMS, according to its SEC filing

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at and on LinkedIn

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